Need Help Treasure location?

[Marki]

Hi! Got an idea. Near Puerto Bello there are two of these very big dungeons, and they have exactely the same structure. I'm sure there is no time limit for treasure maps and I'm sure there is a message when you enter the correct dungeon. Also the treasure map cannot disappear unless you enter the correct dungeon. (I think treasure maps only DO disappear just like that when you do COAS quest or that viking-leif-ericsson-body-changing-quest in Guadeloupe). So if your map is gone I would conclude you entered the correct of the two dungeons, missed the message and just couldn't find the right place in the correct dungeon.
Treasures are always at the same location in this type of dungeons: When you enter the dungeon you will see a wooden pillar on one side. Go this way and then turn always left until you come to the last crossroads, turn right there, it's a short corridor and there is no chest there, just some wood? But the hand appears and voila.

 

[Marki]

There is one location that didn't work for me: Lighthouse of Guadeloupe. I never found the treasure there, never found the correct dungeon or cave, think it just does not exist. A little bug I think or I missed something.
Something else about Lighthouses: There is a wooden plank in these buildings leading you to a chest (second floor? can't remember). At least in one type of Lighthouses, I think there are two in total.
And something about the Cerber sword: If you clean dungeons for the church, some of the skeletons drop a Cerber. Nice.